Nutrisystem

It isn’t the most affordable diet, since it costs between $230 and $320 for 28 days on the woman’s plan, which is slightly more than the US Department of Agriculture’s moderate cost food budget for women between the ages of 19 and 50.

There are three different levels of the plan for women as well as three plans for men.

With each plan, you get frozen meals delivered to your door, which can be convenient, but also means you need to eat pre-packaged frozen food, which can be a turnoff.

If you opt for the priciest plan, you have some choice in terms of “chef-inspired” meals.

Jenny Craig

If you want a plan that offers a range of options, Jenny Craig might be the diet plan for you.

You can choose to work with the program in the privacy of your home or at a local Jenny Craig center.

You are assigned a weight loss consultant who is supposed to help you stay motivated each week.

Along with improving what you eat to lose weight, Jenny Craig also encourages physical activity and exercise.

A trail program with Jenny Craig costs $30 a month for three months. While you have the option of getting meals with the program, the cost doesn’t include food, which can add up quickly.

For example, a single portion of pancakes and vegetarian sausage for breakfast costs $4.89, considerably more than if you made those items yourself.

Other program options with Jenny Craig are the Premium Success program, which is $359 for a year plus 10 percent off food purchases, and the Metabolic Max program, which is $488 for a year, plus 10 percent off food.

It also includes a physical activity tracker.

Medifast

On the Medifast diet plan, you are supposed to lose up to five pounds your first two weeks, then up to two pounds a week after.

The plan includes eating six small meals a day. Five of those meals are meal replacements prepared by Medifast. The sixth one is prepared by you.

A starter kit, which contains four weeks worth of meals, is $363.90.

The price for the food is significantly less than if you were to eat every single meal at a fast food restaurant, but considerably more expensive than if you were to make your meals yourself.

Weight Watchers

Weight Watchers is different from the other diet plans. Since it doesn’t include food or require you to eat certain meals, it might be one of the more affordable diet plans out there and the most flexible.

Weight Watchers is based on a points program. Every food you eat has a certain number of points, determined by the company.

You are allowed to eat a certain number of points each day to help you lose weight, based on your goals.

If you exercise, you are given extra food points to make up for the physical activity.

You have two options with Weight Watchers. You can use the program online or attend in-person meetings in your area.

The online program is usually $29.95 to sign up and an extra $18.95 a month.

You’re entirely on your own with the online version, meaning you don’t have a consultant to interact with or other people who are trying to lose weight to trade stories and tips with.

If there’s a Weight Watchers center in your area, you can choose to attend meetings for motivation and encouragement.

The fee for meetings is around $14 per week, though you can purchase a monthly pass for around $49.95.

If you get the monthly pass, you also get a free subscription to the program’s e-tools, which help you track your points and stay motivated.

Diet plans can give you the initial support you need to lose weight, but might not be so friendly to your wallet.

Before you sign up for one, carefully consider the differences between the costs of the plan and the cost of learning to make simple, healthy meals at home.

Kelly Anderson is a financial planner who blogs about financial advice you can use in your everyday life. Connect with her on Twitter, Facebook and Google+.